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Eternal Risk of Ruin Calculator


The purpose of this calculator is to estimate the probability of ruin, given a positive expected value, standard deviation, bankroll, and infinite play. The calculator assumes the player flat betting and the odds of every trial are the same. The question the calculator answers is what is the probability the player would run out of money, as opposed to growing his bankroll forever. Here is some explanation of each field.

  • Advantage — The player advantage of the bet. For example, in full pay deuces wild, which has a return of 100.762%, the player advantage is 0.00762. Please put the advantage in decimal form, as opposed to a percent.
  • Standard deviation — The square root of the variance of each bet. For example, in full pay deuces wild this value is 5.08.
  • Bankroll — If you lose every bet, this is the number of bets you could make before running out of money. In other words, the amount of money you can risk divided by the amount of each bet. For example, if you had $5,000 and were to play video poker at $1.25 a bet, your bankroll would be $5,000/$1.25 = 4,000.
  • Risk of ruin — Leave this blank. When you click calculate the program will provide an estimate of the probability of running out of money. The alternative is growing the bankroll forever.

Disclaimer: This calculator produces an ESTIMATE only. The greater the bankroll size, the more accurate this estimate will be. In games like video poker, video keno, and slots, where the worst case scenario is losing one unit, I believe this calculator to overstate the chance of ruin.

Calculate the Risk of Ruin

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